He and Scooter have been face to face a few times. Simon is totally not afraid of him. Scooter is a big old 'fraidy cat. He still looks at Simon like, you idiot can't you see I am biggger than you? Then he hisses and runs off. Simon will win him over, he is fearless! If something in the house scares him, like a noise, he will run off, but come right back to investigate. Yes, I think he has been indoors before, especially seeing how quickly he took to litter boxes. I put the little one away, he is using the big guy's. And he comes to me for attention regularly. Altho, when I opened the door this afternoon,he stood at the glass and cried. I don't know if he recognized the porch, or if he just wanted out. Not gonna happen!
Edited to add: They are still curled up in that chair together. I am amazed at Maxie. He is a loving cat, but does not like to cuddle too often with Scooter. Scooter was mine for 2 months before Maxie would let him near. They still don't sleep together very often. Simone wanted it tho, and apparently you don't tell him no. "I'm cute, how could you not love me???"